Character set, variables, constants and keywords Character set: Character set contains alphabets, numbers, and symbols for representing information. Following set shows characters used in C: Alphabets A,B,C,D……………X,Y,Z A,b,c,d…………….x,y,z Numbers 0,1,2,3,4,5,6,7,8,9 Special Symbols ?></.,;’:”[]{}\|*-+_()*&^%$#@! Variables: Variable is an entity which can change or it is a name of the memory location. It should start with only alphabets or underscore. Also called identifiers. e.g. int A=10; consider memory location 1000 in a computer’s memory where 10 value is stored. So we can retrieve or modify value 10 through variable A. Constants: Constant is an entity which cannot change. e.g. int A=10; 10 is a constant. Types of constants: 1.Primary Constants 2.Secondary Constants Constants Range Integer -32768 to +32767 Float -3.4e38 to